Vinpocetine and pyritinol: a new model for blood rheological modulation in cerebrovascular disorders—a randomized controlled clinical study

Whole Blood Viscosity and Cerebral Blood Flow in Acute Ischemic Stroke

Existing effective treatments for ischemic stroke restore blood supply to the ischemic region using thrombolysis or mechanical removal of clot. However, it is increasingly recognized that successful removal of occlusive thrombus from the large artery-recanalization, may not always be accompanied by successful restoration of blood flow to the downstream tissues-reperfusion. Ultimately, brain tissue survival depends on cerebral perfusion, and a functioning microcirculation. Because capillary diameter is often equal to or smaller than an erythrocyte, microcirculation is largely dependent on erythrocyte rheological (hemorheological) factors such as whole blood viscosity (WBV). Several studies in the past have demonstrated elevated WBV in stroke compared with healthy controls. Also, elevated WBV has shown to be an independent risk factor for stroke. Elevated WBV leads to endothelial dysfunction, decreases nitric oxide-dependent flow-mediated vasodilation, and promotes hemostatic alterations/thrombosis, all leading to microcirculation sludging. Compromised microcirculation further leads to decreased cerebral perfusion. Hence, modulating WBV through pharmacological agents might be beneficial to improve cerebral perfusion in stroke. This review discusses the effect of elevated WBV on endothelial function, hemostatic alterations, and thrombosis leading to reduced cerebral perfusion in stroke.

Vinpocetine alleviated alveolar epithelial cells injury in experimental pulmonary fibrosis by targeting PPAR-γ/NLRP3/NF-κB and TGF-β1/Smad2/3 pathways

This study aimed to investigate the potential anti-fibrotic activity of vinpocetine in an experimental model of pulmonary fibrosis by bleomycin and in the MRC-5 cell line. Pulmonary fibrosis was induced in BALB/c mice by oropharyngeal aspiration of a single dose of bleomycin (5 mg/kg). The remaining induced animals received a daily dose of pirfenidone (as a standard anti-fibrotic drug) (300 mg/kg/PO) and vinpocetine (20 mg/kg/PO) on day 7 of the induction till the end of the experiment (day 21). The results of the experiment revealed that vinpocetine managed to alleviate the fibrotic endpoints by statistically improving (P ≤ 0.05) the weight index, histopathological score, reduced expression of fibrotic-related proteins in immune-stained lung sections, as well as fibrotic markers measured in serum samples. It also alleviated tissue levels of oxidative stress and inflammatory and pro-fibrotic mediators significantly elevated in bleomycin-only induced animals (P ≤ 0.05). Vinpocetine managed to express a remarkable attenuating effect in pulmonary fibrosis both in vivo and in vitro either directly by interfering with the classical TGF-β1/Smad2/3 signaling pathway or indirectly by upregulating the expression of Nrf2 enhancing the antioxidant system, activating PPAR-γ and downregulating the NLRP3/NF-κB pathway making it a candidate for further clinical investigation in cases of pulmonary fibrosis.

Nootropics as Cognitive Enhancers: Types, Dosage and Side Effects of Smart Drugs

Nootropics, also known as “smart drugs” are a diverse group of medicinal substances whose action improves human thinking, learning, and memory, especially in cases where these functions are impaired. This review provides an up-to-date overview of the potential effectiveness and importance of nootropics. Based on their nature and their effects, this heterogeneous group of drugs has been divided into four subgroups: classical nootropic compounds, substances increasing brain metabolism, cholinergic, and plants and their extracts with nootropic effects. Each subgroup of nootropics contains several main representatives, and for each one, its uses, indications, experimental treatments, dosage, and possible side effects and contraindications are discussed. For the nootropic plant extracts, there is also a brief description of each plant representative, its occurrence, history, and chemical composition of the medicinal part. Lastly, specific recommendations regarding the use of nootropics by both ill and healthy individuals are summarized.

Changes in the Blood Viscosity in Patients With SARS-CoV-2 Infection

Coronavirus disease 2019 (COVID-19) is caused by a novel virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2-induced hyperinflammation together with alteration of plasma proteins, erythrocyte deformability, and platelet activation, may affect blood viscosity. Thus, this review aimed to study the link between SARS-CoV-2 infection and alteration of blood viscosity in COVID-19 patients. In order to review findings related to hyperviscosity in COVID-19, we suggested a protocol for narrative review of related published COVID-19 articles. Hyperviscosity syndrome is developed in different hematological disorders including multiple myeloma, sickle cell anemia, Waldenstorm macroglobulinemia, polycythemia, and leukemia. In COVID-19, SARS-CoV-2 may affect erythrocyte morphology via binding of membrane cluster of differentiation 147 (CD147) receptors, and B and 3 proteins on the erythrocyte membrane. Variations in erythrocyte fragility and deformability with endothelial dysfunction and oxidative stress in SARS-CoV-2 infection may cause hyperviscosity syndrome in COVID-19. Of interest, hyperviscosity syndrome in COVID-19 may cause poor tissue perfusion, peripheral vascular resistance, and thrombosis. Most of the COVID-19 patients with a blood viscosity more than 3.5 cp may develop coagulation disorders. Of interest, hyperviscosity syndrome is more commonly developed in vaccine recipients who had formerly received the COVID-19 vaccine due to higher underlying immunoglobulin concentrations, and only infrequently in those who have not received the COVID-19 vaccine. Taken together, these observations are untimely too early to give a final connotation between COVID-19 vaccination and the risk for development of hyperviscosity syndrome, consequently prospective and retrospective studies are necessary in this regard.

COVID-19 and erythrocrine function: The roller coaster and danger

Erythrocrine function refers to erythrocytes’ ability to synthesize and release active signaling molecules such as ATP and nitric oxide (NO). Erythrocyte NO regulates its deformability and increases its perfusion and circulation that prevent tissue hypoxia. Recently, there is a connotation between SARS-CoV-2 infection and erythrocrine function due to alteration in the release of NO and ATP from erythrocytes. SARS-CoV-2 binds erythrocyte band3 protein, which has a similar characteristic of ACE2, leading to alteration of erythrocyte physiology like oxygen transport with development of hypoxia. Similarly, SARS-CoV-2 infection activates erythrocyte protein kinase C alpha (PKC-α), causing significant changes in the erythrocyte functions. The erythrocytes can bind SARS-CoV-2 and its active particles with subsequent virus delivery to the liver and spleen macrophages. Thus, the erythrocytes act as elimination for SARS-CoV-2 in COVID-19. Moreover, the erythrocyte stored, release sphingosine-1 phosphate (S1P) improves endothelial and regulates lymphocyte functions. SARS-CoV-2 ORF8 protein binds the porphyrin part of hemoglobin heme at the β1 chain, causing hemolysis and dysfunctional hemoglobin to reduce oxygen-carrying capacity. In conclusion, SARS-CoV-2 infection and associated pro-inflammatory disorders lead to abnormal erythrocrine function with subsequent inflammatory complications and endothelial dysfunction due to deficiency of protective released molecules (NO, G1P, and ATP) from functional erythrocytes. In vitro, preclinical, and clinical studies are mandatory in this regard.

Role of vinpocetine in ischemic stroke and poststroke outcomes: A critical review

Vinpocetine (VPN) is a synthetic ethyl-ester derivative of the alkaloid apovincamine from Vinca minor leaves. VPN is a selective inhibitor of phosphodiesterase type 1 (PDE1) that has potential neurological effects through inhibition of voltage-gated sodium channel and reduction of neuronal calcium influx. VPN has noteworthy antioxidant, anti-inflammatory, and anti-apoptotic effects with inhibitory effect on glial and astrocyte cells during and following ischemic stroke (IS). VPN is effective as adjuvant therapy in the management of epilepsy; it reduces seizure frequency by 50% in a dose of 2 mg/kg/day. VPN improves psychomotor performances through modulation of brain monoamine pathway mainly on dopamine and serotonin, which play an integral role in attenuation of depressive symptoms. VPN recover cognitive functions and spatial memory through inhibition of hippocampal and cortical PDE1 with augmentation of cyclic adenosin monophosphate and cyclic guanosin monophosphate ratio, enhancement of cholinergic neurotransmission, and inhibition of neuronal inflammatory mediators. Therefore, VPN is an effective agent in the management of IS and plays an integral role in the prevention and attenuation of poststroke epilepsy, depression, and cognitive deficit through direct cAMP/cGMP-dependent pathway or indirectly through anti-inflammatory and antioxidant effects.

Vinpocetine Improves Oxidative Stress and Pro-Inflammatory Mediators in Acute Kidney Injury

Background:

Gentamicin-induced-acute kidney injury (AKI) is a multifaceted phenomenon which previously linked to the oxidative stress only. Vinpocetine prevents reactive free radical generation which contributed in reduction of damage. Therefore, objective of the present study was to investigate the renoprotective effect of vinpocetine on gentamicin-induced-AKI in rats.

Methods:

Thirty Sprague Dawley Male rat were divided into three groups. Control group (n = 10): Rats treated with distilled water + intra-peritoneal injection of normal saline 2 ml/kg/day. Gentamicin group (n = 10): Rats treated with distilled water + intra-peritoneal injection of gentamicin 100 mg/kg/day. Vinpocetine group (n = 10): Rats treated with vinpocetine + intra-peritoneal injection of gentamicin 100 mg/kg/day. Blood urea and serum creatinine were estimated by auto-analyzer. Serum malondialdehyde (MDA), superoxide dismutase (SOD), Neutrophil Gelatinase Associated Lipocalin (NGAL), kidney injury molecules (KIM-1), and Cystatin-c were measured by ELISA kit methods.

Results:

Vinpocetine led to significant renoprotective effect on gentamicin induced-AKI through amelioration of blood urea and serum creatinine compared with gentamicin group P < 0.01. Vinpocetine improved oxidative stress through reduction of MDA serum level and elevation of SOD significantly compared with gentamicin group P = 0.001 and P = 0.03, respectively. Indeed, vinpocetine reduced glomerular and renal tubular injury via reduction of inflammatory biomarkers including KIM-1, NGALand Cystatin-c sera levels significantly P < 0.01 compared to gentamicin group.

Conclusions:

Vinpocetine leads to significant attenuation of gentamicin-induced-AKI through modulation of oxidative stress and pro-inflammatory pathway.

Effect of hemorheological parameters on myocardial injury after primary or elective percutaneous coronary intervention

BACKGROUND

Abnormal blood viscosity favors atherosclerosis owing to endothelial dysfunction and changes in shear stress. Its effect on coronary microvasculature during percutaneous coronary intervention (PCI) is still unknown. We aimed to investigate the role of hemorheological parameters in the incidence of microvascular obstruction (MVO) and the periprocedural necrosis after primary or elective PCI, and secondarily, we evaluated their prognostic significance.

MATERIALS AND METHODS

We enrolled 25 patients with ST-elevation myocardial infarction (STEMI), 30 patients with non-ST-elevation myocardial infarction (NSTEMI), and 30 patients with stable angina (SA) undergoing PCI. MVO in patients with STEMI and periprocedural necrosis in patients with NSTEMI and those with SA were assessed using angiographic/electrocardiographic and laboratory methods, respectively. Hemorheological profile included blood viscosity (η) at shear rates 200 s and 1 s, the erythrocyte aggregation index (η1/η200), and plasma viscosity. Major adverse cardiovascular events occurrence was evaluated at follow-up.

RESULTS

Patients with STEMI experiencing angiographic MVO (28%) had higher η200 (5.42±1.28 vs. 3.98±1.22 mPa[BULLET OPERATOR]s; P=0.015). Similarly, patients with STEMI experiencing electrocardiographic MVO (56%) had higher η200 (4.58±0.36 vs. 3.94±0.19 mPa[BULLET OPERATOR]s; P<0.001). Among patients with SA and patients with NSTEMI, those experiencing periprocedural necrosis (23.3%) had higher η200 (5.30±0.86 vs. 4.37±0.88 mPa[BULLET OPERATOR]s; P=0.001), η1 (19.52±9.62 vs. 13.29±7.65 mPa[BULLET OPERATOR]s; P=0.015) and η1/η200 values (3.64±1.50 vs. 2.72±0.92; P=0.007). These significant differences were maintained after adjustment for age, sex, and cardiovascular risk factors. At follow-up (30±6 months), 25 (29.4%) patients presented major adverse cardiovascular events, and they had higher η200 (5.18±1.00 vs. 4.25±1.01 mPa[BULLET OPERATOR]s; P<0.001).

CONCLUSION

In patients undergoing either urgent or elective PCI, hemorheological parameters might contribute to myocardial injury and, if furtherly confirmed, to an unfavorable outcome.

[Possibilities of cavinton therapy regimen for infusions and cavinton comforte in acute and early recovery periods after ischemic stroke]

AIM

To study the efficacy of a current regimen of treatment with cavinton for infusions and cavinton comforte in patients with ischemic stroke in acute and early recovery periods and to evaluate an impact of treatment on erythrocyte deformity using atomic power microscopy.

MATERIAL AND METHODS

One hundred and sixty-four patients with hemispheric ischemic stroke, aged from 30 to 79 years, were randomized into main (n=100) and control (n=64) groups. Patients of the main group received complex treatment (basic therapy and cavinton R for drop infusions (10 intravenously during 10 days) followed by cavinton R comforte in dose 10 mg, 1 tablet 3 times a day during 90 days). Patients of the control group received basic therapy only. NIHSS, the Rankin scale, the Barthel index, MMSE, MоCA, the Rivermead scale, Beck depression scale, HADS were used to measure the severity of patient's state. To study the erythrocyte membrane by estimating Young's modulus, dry preparations were made with the following scanning of erythrocytes using atomic power microscopy.

RESULTS

Positive changes on all scales were observed in both groups. Higher scores on NIHSS, Rankin, Barthel, MоCA, MMSE, Rivermead mobility index were found in the main group compared to the controls. There were no differences in scores on the Beck depression scale and HADS. A decrease in Young's modulus was found in the main group while in the control group this index remained unchanged.

CONCLUSION

More rapid and complete regression of neurological deficit, better recovery of self-care function, cognitive function and social activity, an increase in erythrocyte membrane elasticity were found in the main group compared to the control one. These results indicate the efficacy of cavinton R and cavinton R comforte in the regimen used in complex treatment in acute and early recovery periods after ischemic stroke.

Studies on Pharmacokinetic Drug Interaction Potential of Vinpocetine

Background

Vinpocetine, a semi-synthetic derivative of vincamine, is a popular dietary supplement used for the treatment of several central nervous system related disorders. Despite its wide use, no pharmacokinetic drug interaction studies are reported in the literature. Due to increasing use of dietary supplements in combination with conventional drugs, the risk of adverse effects is on the rise. As a preliminary step to predict a possibility of drug interaction during concomitant use of vinpocetine and conventional drugs, this study was carried out to evaluate the effects of vinpocetine on three main regulators of pharmacokinetic drug interactions namely, cytochromes P450 (CYPs), P-glycoprotein (P-gp), and Pregnane X receptor (PXR).

Methods

Inhibition of CYPs was evaluated by employing recombinant enzymes. The inhibition of P-gp was determined by calcein-AM uptake method in transfected and wild type MDCKII cells. Modulation of PXR activity was monitored through a reporter gene assay in HepG2 cells.

Results

Vinpocetine showed a strong inhibition of P-gp (EC₅₀ 8 μM) and a moderate inhibition of recombinant CYP3A4 and CYP2D6 (IC₅₀ 2.8 and 6.5 μM) with no activity towards CYP2C9, CYP2C19 and CYP1A2 enzymes. In HLM, competitive inhibition of CYP3A4 (IC₅₀ 54 and K_i 19 μM) and non-competitive inhibition of CYP2D6 (IC₅₀ 19 and K_i 26 μM) was observed. Activation of PXR was observed only at the highest tested concentration of vinpocetine (30 μM) while lower doses were ineffective.

Conclusion

Strong inhibition of P-gp by vinpocetine is indicative of a possibility of drug interactions by altering the pharmacokinetics of drugs, which are the substrates of P-gp. However, the effects on CYPs and PXR indicate that vinpocetine may not affect CYP-mediated metabolism of drugs, as the inhibitory concentrations are much greater than the expected plasma concentrations in humans.